-
Notifications
You must be signed in to change notification settings - Fork 0
/
reconnector.go
113 lines (102 loc) · 3.24 KB
/
reconnector.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
/*
* Copyright (c) 2024 Lynn <lynnplus90@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package mqtt
import (
"errors"
"github.com/lynnplus/go-mqtt/packets"
"sync/atomic"
"time"
)
// ReConnector is an interface that implements the client disconnection and reconnection flow.
//
// After the client successfully establishes a connection,
// if the connection is lost, Connection Lost will first be called to reconnect.
// If the connection fails to be established during the reconstruction process,
// Connection Failure will be called to retry the flow.
type ReConnector interface {
// ConnectionLost is called when the connection is lost or the server sends a disconnection packet.
// It returns a timer to indicate when the client should reinitiate the connection.
// If the timer is empty, it means that no reconnection will be initiated.
ConnectionLost(pkt *packets.Disconnect, err error) *time.Timer
// ConnectionFailure is called when the connection fails to be established.
ConnectionFailure(dialer Dialer, err error) (Dialer, *time.Timer)
// Reset is called when the connection is successful or initialization is required.
Reset()
}
type AutoReConnector struct {
AutoReconnect bool //Whether to automatically reconnect after the connection is lost
ConnectRetry bool //Whether to retry after the first connection failure
MaxRetryDelay time.Duration
count atomic.Uint32
lastLost time.Time
}
func NewAutoReConnector() *AutoReConnector {
return &AutoReConnector{
AutoReconnect: true,
ConnectRetry: true,
MaxRetryDelay: 5 * time.Minute,
}
}
func (a *AutoReConnector) Reset() {
a.count.Store(0)
}
func (a *AutoReConnector) ConnectionLost(pkt *packets.Disconnect, err error) *time.Timer {
if !a.AutoReconnect {
return nil
}
if pkt != nil {
if pkt.ReasonCode == packets.ServerBusy || pkt.ReasonCode == packets.ServerShuttingDown {
return time.NewTimer(15 * time.Second)
}
}
now := time.Now()
if now.Sub(a.lastLost) < (5 * time.Second) {
return time.NewTimer(10 * time.Second)
} else {
a.lastLost = now
return time.NewTimer(2 * time.Second)
}
}
func (a *AutoReConnector) allowRetry(code packets.ReasonCode) bool {
switch code {
case packets.ServerBusy,
packets.ServerUnavailable:
return true
}
return false
}
func (a *AutoReConnector) ConnectionFailure(dialer Dialer, err error) (Dialer, *time.Timer) {
if !a.ConnectRetry {
return dialer, nil
}
var reasonErr *packets.ReasonCodeError
if errors.As(err, &reasonErr) {
if !a.allowRetry(reasonErr.Code) {
return dialer, nil
}
}
d := a.count.Load() * 2
if d < 5 {
d = 5
}
delay := time.Duration(d) * time.Second
if delay > a.MaxRetryDelay {
delay = a.MaxRetryDelay
}
timer := time.NewTimer(delay)
a.count.Add(1)
return dialer, timer
}